“Steepest slope ever.”
By Steven Goddard
We have been hearing a lot about how the decline in Arctic ice is following the “steepest slope ever.” The point is largely meaningless, but we can have some fun with it. The Bremen Arctic/Antarctic maps are superimposed above, showing that ice in the Antarctic is at a record high and growing at the “steepest slope ever.” You will also note that most of the world’s sea ice is located in the Antarctic. But those are inconvenient truths when trying to frighten people into believing that “the polar ice caps are melting.”
There are several favorite lines of defense when trying to rationalize away the record Antarctic ice.
1. It is the Ozone Hole – which is also the fault of evil, American SUV drivers. That is a nice guilt trip, but sadly the Ozone Hole doesn’t form until August and is gone by December. Strike one.
The next one is to point out that some regions of the west side of the tiny Antarctic Peninsula have been warming. Never mind that the Antarctic Peninsula is an active volcanic ridge, and that the waters around it have not shown any significant warming. Strike two.
UAH shows Antarctica cooling slightly over the last 30 years.
The third favorite line of defense is to argue that “we expected Antarctica to warm more slowly because of the mass of the southern oceans.” Nice try – “slower warming” is not the same as “cooling.” Strike three.
(The AGW view of Antarctica is every bit as irrational as FIFA’s stand that not having instant replays somehow helps the referees’ reputations.)
On to the Arctic. First graph is a JAXA comparison of 2006, 2007 and 2010. Note that 2006 and 2007 were nearly identical, until early July. The main difference between 2006 (second highest in the JAXA record) and 2007 (lowest in the JAXA record) was that strong southerly winds compacted and melted the ice in 2007. As you can see below, the summer extent numbers are nearly meaningless before July/August. So far, 2010 is tracking very closely with both 2006 and 2007, and it appears the three will intersect in about a week.
Let’s take a closer look at the mechanisms using the PIPS ice and wind data. If we watch the movement of Arctic ice during the summer, we can see that when the winds blow away from the pole (i.e. from the north) the ice expands. When the wind blows from the south, the ice contracts. Some summers, the winds alternate between north and south, and the ice extent changes less during the summer – like in 2000 below.
Other years, like 2007, the summer winds blew consistently from the south, causing the ice to melt at a faster pace and compress towards the north.
So basically, it is weather (wind) rather than climate which controls the summer minimum. Of course, it is harder to compress and melt thick ice than thin ice – so the thickness of the ice is important. It is too early to determine if 2010 will see winds like 2007, or if summer winds this year will be more like 2006.
No one has demonstrated much skill at forecasting winds six weeks in the future, so it is really anybody’s guess what wil happen this summer. Before August arrives, the pattern should be clear.
The video below shows ice movement near Barrow, AK over the past 10 days.
The winds were blowing strongly and contracting the ice edge until the last few days, when they died down. Over the past two or three days, the ice edge has not moved very much.
Over the last week, almost all of the ice loss in the Arctic has been in the Hudson Bay, as seen in the modified NSIDC image below in red. The Hudson Bay is normally almost ice free in September, so the recent losses are are almost meaningless with respect to the summer minimum.
The modified NSIDCimage below shows ice loss since early April. All of the areas shown in red are normally ice free in September.
The modified NSIDC image below is a comparison of 2010 vs 2007. Areas of red had more ice in 2007. Areas of green have more ice in 2010.
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The modified NSIDC image below shows the current deficiencies in red. Again, all of those areas are normally ice free in September, so they don’t tell us much about the summer minimum.
Below is my forecast for the remainder of the summer.
But it all depends on the wind.
From the 9th century to the 13th century almost no ice was reported there. This was the period- of Norse colonization of’ Iceland and Greenland. Then, conditions worsened and the Norse colonies declined. After the Little Ice Age of 1650 to 1840 the ice began to vanish near Iceland and had almost disappeared when the trend re versed, disastrously crippling Icelandic fisheries last year.
The thick ice that has for ages covered the Arctic Ocean at the pole has turned to water, recent visitors there reported yesterday. At least for the time being, an ice-free patch of ocean about a mile wide has opened at the very top of the world, something that has presumably never before been seen by humans and is more evidence that global warming may be real and already affecting climate. The last time scientists can be certain the pole was awash in water was more than 50 million years ago.
Is it possible that the IPCC is trying to rewrite the history books?
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Anu
Every school child in America has been taught that the polar ice caps are melting, because their teachers have been fed this garbage by government scientists and their proxies.
I must have missed the realclimate post where they tried to set the record straight. Perhaps Chu made a speech saying that the polar ice caps aren’t melting?
Give me a break.
richcar 1225,
I did read that it was expected to be all systems go by October, but I can no longer find that reference.
phlogiston says: “…This looks very important (I navigated to the paper on the moon – not being a black body) and points to a component in global heat budget that has been ignored – heat storage of the land surface.”
I’ve heard that land heat capacity is very small because of the insulating value of dirt, sand, etc., relative to water. But do we know for sure that land heat capacity doesn’t appear in GCM’s?
richcar 1225,
This has a little more information:
http://www.sciencepoles.org/articles/article_detail/mark_drinkwater_on_cryosat-2_and_its_mission/
“By July 2010 we hope to start distributing data to a limited number of scientists – with a caveat of course – before we open distribution to a much wider user community. The validation that would have to take place before mid-summer will probably give us enough confidence to allow our calibration and validation team to really get a solid understanding of the data and be able to recognize what kind of margin of error measurements can produce and why and correct for that.
We’re first going to start distributing data to a select team of external scientists who applied to be testers of the initial data products. They’ll provide us with feedback on the quality of the product, which will help us revise the processing of the products to try and get the highest possible quality data out to the broader user community.”
Bravo Steve! An encore performance. Perhaps your best Sea Ice News update yet. you may want to check your very opening graph however. It seems you’ve got the Antarctic sea ice topping out each year close to 18 million sq. km. It usually tops out around 15.5 million. Please also note that it usually falls below what the Arctic traditionally has at the minimum, at around 2.0 million, where as the Arctic has traditionally been around 6 million or so (except for these last few years, as we all know)
A few things out of the gate:
Back in March, when you and many other skeptics were tooting your horns as the Arctic Sea ice “bumped” up to near normal conditions, I hope you recall that I (and others) kept pointing back to the entire winter history of the ice when it was at or very near lows during the winter and urging caution over the giddy skeptic pronouncement that the Arctic Sea ice had recovered. Thick, melt resistant ice simply doesn’t form in a few weeks, and so, those of us who’ve studied the ice, professionally or non, knew that what goes up that fast, must come down that fast, especially considering the fact that the Arctic as a whole has seen (and continues to see) temps running several degrees above average. The “bump up” was bound to go bust, and so it has, with the biggest March 31 to June 28 decline on the record books.
Many have asked why we should focus so much on the Arctic and ignore the Antarctic and its record positive slope. Well, the answer is: no professional who studies the cryosphere is ignoring the Antarctic. Hundreds, or perhaps thousands of scientists are studying it every day. The fact is however, that the weather of the N. Hemisphere, where the bulk of the worlds populations resides, is more influenced by the Arctic than the Antarctic.
But I want to cut right to the issue of wind, as it really IS central to what is going on in the Arctic in many complex ways, but most salient to the discussion here is the change in the winds brought about by the very warming of the Arctic itself. Julienne has spoke about it at length here, and mentioned some of the critical studies related to the Dipole Anomaly. This seems to be one of the real positive feedback events that may be traceable back to warmer Arctic waters releasing more heat later into the season and altering long term wind patterns. Heat and wind are integrally related, and the Dipole Anomaly seems to be self-reinforcing, and become less of an anomaly 9as it was just a few years ago) and more of a regular feature of the Arctic weather patterns.
The DA does many things. It opens up the normally closed wind circulation of the Arctic, bringing more warmth to the Arctic, but it also shunts more cold air out of the Arctic down south– hence the reason that the Arctic could see warmer winters while we see tougher ones down south here. Remember my comments this past winter when it was snowing in Florida but 35 degrees F in Greenland ? This is where the DA becomes a positive feedback mechanism, in that the warmer things get, the stronger and more frequent the DA appears to become.
I must applaud you Steve for putting it all on the line in creating your little graph that shows how things are going to progress this summer. You must believe that there is indeed a whole bunch of hidden volume (via your PIPs 2.0 model) that is going to prove tough to melt once the fringe areas melt. I happen to believe quite the opposite. I think PIPS 2.0 thickness data is pretty much worthless, and I think the direct “on the ice” observations of people like David Barber, and his finding the ice far more weak and unlike anything they’d expected for multi-year ice is confirmation that the PIPS 2.0 really does have it wrong (as many professionals ignore it for that reason), and that PIOMAS is much closer with projections of 4.4 to 4.7 million sq. km. which are far closer because they’ve got the volume data closer than PIPS 2.0 could ever.
My long standing projection of 4.5 million sq. km., which I made back in March (or was it February?), but anyway…it still looks pretty good to me, especially in looking how the Dipole Anomaly may be running strong, and I may even revise it DOWNWARD a bit around July 15, based on the early July melt. But you are right on one point– the exact final number for Arctic sea ice extent is really up to the weather, but this year has seen no recovery in sea ice, (quite the opposite) and so skeptics will have to look elsewhere to find issues with AGW models.
I also to think the offer by one poster here for us to do an after the season analysis of why we were right/wrong and what we learned is a fantastic idea.
stevengoddard says:
June 28, 2010 at 6:59 pm
GeoFlynx
The anomaly data is normalised. The fact that the global anomaly data has remained constant has absolutely nothing to do with seasons. That is one reason why people normalise data – to remove cyclical behaviour.
GeoFlynx –
OK, I admit the “season” thing was a bit of a good natured tease based on your wording. However, if we do as you say and normalize the global sea ice data to remove the higher frequency seasonal trend it looks like this:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
If we accept this graph and its authors, global sea ice is not balanced and shows a clear decline.
Anu says: “Google search for ‘climate skeptics are crazy’ returns about 163,000 results….”
Anus’ statement is based on strange logic, once again. A properly parsed Google search for “climate skeptics are crazy” gives 99 results, not 163,000. Either Anu’s Google searches are incompetent, or he’s unable to deal with facts without fudging them.
Here’s a good example of the “Polar Ice Caps Melting” in the MSM, including a “pretty scary” and “unprecedented” interview with Walt Meier of the NSIDC:
My respect for Walt just melted…
R. Gates says: June 28, 2010 at 8:47 pm
“you may want to check your very opening graph however. It seems you’ve got the Antarctic sea ice topping out each year close to 18 million sq. km. It usually tops out around 15.5 million.”
I assume you are speaking of Antarctic Sea Ice Area:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.area.antarctic.png
whereas Steve posted a chart on Antarctic Sea Ice Extent:
http://www.iup.uni-bremen.de:8084/amsr/ice_ext_s.png
R. Gates says: June 28, 2010 at 8:47 pm
“Many have asked why we should focus so much on the Arctic and ignore the Antarctic and its record positive slope. Well, the answer is: no professional who studies the cryosphere is ignoring the Antarctic. Hundreds, or perhaps thousands of scientists are studying it every day. The fact is however, that the weather of the N. Hemisphere, where the bulk of the worlds populations resides, is more influenced by the Arctic than the Antarctic.”
I am not concerned with the number of scientists studying the Antarctic, nor the minor impact that Arctic sea ice changes may have on “the weather of the N. Hemisphere.”
My question for you is, which of Earth’s poles’ sea ice offers a more accurate proxy of Earth’s temperature and temperature trend, and why?
R Gates,
You are confusing area with extent.
http://www.iup.uni-bremen.de:8084/amsr/ice_ext_s.png
Ray says:
June 28, 2010 at 12:32 pm
“Just for fun I did the first derivative of the ice extent on the JAXA graph. The rate of decline has passed its peak around the 10th of June… so the decline speed is actually slowing down already.
Are you delusional? 2010; 10 to 19 June melt; 588,438 KM2 @ur momisugly 65,382 KM2 per day
June 17 to 27 melt; 695,156 KM2 @ur momisugly 77,240 KM2 per day
Comparing with 2009 and taking the late melt start of 31 March 2010 as starting point (both years had 14.41 KM2 on that date), 2010 lost 5.82 million KM2 and 2009 lost 3.94 million KM2. 2010 leads 2009 by 1.34 million KM2.
2009 had four 100,000+ KM2 melt days between May 19 (the first 100,000+ KM2 day) and today, while 2010 has eight of which four were before May 19.
Using IRAC-JAXA data.
In 2009, between 29-6 and 25-7 there were ten 100,000+ melt days. I expect that 2010 will have at least as many such days, but probably more, giving it a total of 18. The total for 2009 was 15 days, the last one on 25-7. This makes a mockery of the “arctic has recovered” claim.
In order for 2010 to drop to 2007 (4.25 KM2) it needs to melt a further 4.88 KM2 @ur momisugly 62,594 KM2 per day, using 13 September 2009 as end date. Over that period 2009 melted 5.77 KM2 @ur momisugly 74,034 per day.
Conclusion; The 2010 melt does not even have to match the 2009 melt from now on. If it were to do so, the ice extent would be 890,230 KM2 below 2009 or 4.36 million KM2, just 110,000 KM2 above 2007. I don’t discount the possibility of 2010 setting a new record. Just confirmed, most recent melt 142,187 KM2, dropping the ice extent to 8,98 million KM2. (IRAC-JAXA) 28 June.
Apparently someone missed this article from six weeks ago.
http://wattsupwiththat.com/2010/05/15/sea-ice-graphs-have-limited-predictive-value/
While it speaks for itself, please insert the word “million” after numbers 4.41, 4.25, 4.88 and 5.77
Regarding this statement in the article:
“Never mind that the Antarctic Peninsula is an active volcanic ridge, and that the waters around it have not shown any significant warming.”
Can you address this presentation and paper?
http://www.whoi.edu/cms/files/Gille_50024.pdf
Summary slide says this: “Southern Ocean has warmed significantly over last 50+ years, and warming is concentrated in the ACC.” [ACC = Antarctic Circumpolar Current]
http://www-pord.ucsd.edu/~sgille/pub_dir/i1520-0442-21-18-4749.pdf“ entitled “Decadal Scale Temperature Trends in the Southern Hemisphere Ocean”, Journal of Climate, 2008.
A short summary from NERC dated 2007 says the following:
As far as I can tell from these links, the ACC constitutes the waters around the Antarctic Peninsula. These sources purport to indicate that the ACC is warming.
One final question: why is the plot shown below the quote that initiates this post a plot of lower tropospheric temperatures, while the quote is actually about sea surface temperatures?
“Is it possible that the IPCC is trying to rewrite the history books?”
The hockeystick and ClimateGate emails shows that this was indeed the intention.
Delete LIA and MWP and get a hockeystick. The warmers try the same with Arctic Ice.
Thats why they get so frenetic whenever historic facts about an icefree north pole comes up. They hate that.
Why? Because it indicates natural cycles.
-They hate natural cycles.
-They love Hockeysticks.
Thats why they are called The HockeyTeam.
http://www.ktuu.com/Global/story.asp?S=10140922
Oakden,
GISS shows a whopping 0.2C rise in SSTs around the Antarctic Peninsula over the last 100 years.
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=5&sat=-1&sst=3&type=trends&mean_gen=05&year1=1910&year2=2010&base1=1951&base2=1980&radius=250&pol=reg
In three days, the slope of the Arctic extent graph will begin to drop off.
Mark it on your calendar.
GISS shows no change in SSTs around the Antarctic Peninsula over the last 50 years.
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=5&sat=-1&sst=3&type=trends&mean_gen=0112&year1=1960&year2=2009&base1=1951&base2=1980&radius=250&pol=reg
I don’t think the Antarctic extent is getting bigger due to colder ocean temps due to no El Nino and end of PDO cycle, if you look at current SST anomaly it is mainly same or higher than average
http://weather.unisys.com/surface/sst_anom.html
Andy
Those NSIDC maps are not quite what they should be. Gulf of Finland and Gulf of St.Lawrence have been ice-free quite a while.
Apparently Africa has it’s own El Nino:
http://207.190.239.143/Whats_New/Archives/Benguela_Currents.pdf
Anu says:
June 28, 2010 at 8:12 pm
And Google search for ‘climate skeptics are crazy’ returns about 163,000 results.
What’s your point ?
Your arguments are always shallow. But let’s go with that for a moment anyway: if what you call “skeptics” don’t have a real argument and they are crazy then why do you spend so much time here? It’s because you’re afraid? You must not be convinced of your own arguments.
stevengoddard says:
June 28, 2010 at 9:42 pm
R Gates,
You are confusing area with extent.
Don’t expect him to know what he’s doing.